The present invention relates generally to electric switches, and more particularly to a weather-proof coaxial switch assembly having a magnetic locking feature which prevents unauthorized actuation.
In cable antenna television (CATV) systems radio frequency (RF) signals are transmitted to the TV receivers of individual subscribers by means of a coaxial cable. In order to provide a means by which service can be terminated to a subscriber various switch assemblies have been proposed for insertion in the line to the subscriber to interrupt transmission and to substitute a passive termination corresponding to the characteristic impedance of the coaxial cable. These assemblies have been both of a type intended for actuation by an electrical control signal from a central office, as described in copending application Ser. No. 741,606, filed Nov. 15, 1976, and assigned to the present assignee, and of a type intended for manual actuation by service personnel, as described in the copending application Ser. No. 599,692, filed July 28, 1975, and also assigned to the present assignee.
One requirement of coaxial switches of the latter manually-actuated type is that they be secure against unauthorized actuation, since such switches are often installed in or on utility poles, or in utility boxes or other accessible locations wherein they are available for operation by servicemen for either connecting or disconnecting the CATV cable to the subscriber depending on whether the service is desired or has been paid for. Another requirement of such switches is that the locking arrangement utilized therein provide reliable operation even after exposure to weather for long periods of time, and without the need for periodic maintenance. It is for this reason that magnetic locking arrangements, wherein the switch is unlocked by means of a magnetic-key unit such as in the aforementioned application Ser. No. 599,692, instead of by a tumbler and cylinder type lock susceptible to corrosion, are preferred for such applications. The present invention provides an improved construction for such a magnetically-locked switch which provides improved performance and is less expensive to construct.
Accordingly, it is a general object of the present invention to provide a new and improved magnetically-locked coaxial switch.
It is another object of the present invention to provide a new and improved magnetically-locked coaxial switch which provides improved performance and is less costly to manufacture.